This invention relates to a solid state watch in which a frequency standard is divided down to provide a highly accurate one Hz signal. This signal drives a time and calendar computer in which a series of registers store binary encoded values corresponding to seconds, minutes, hours, days and months. The binary encoded information provided by the time and calendar computer is decoded and displayed on a visual read out. The current state of the art enables essentially the entire electronic circuitry of the watch to be constructed as a single large scale integrated circuit. In order to reduce battery consumption to a minimum, this integrated circuitry is advantageously provided by complementary MOS circuitry or other circuit types having inherently low power consumption.
The type of readout display which has achieved overwhelming popularity in the consumer market is formed from a plurality of light emitting diodes arranged to display Arabic numerals. This type of readout, however, requires a fair amount of electrical power such that it is impractical to continuously energize the optical display. Accordingly, it has been the contemporary practice to provide a series of push button switches for each of the time display and time setting sequences. Thus, all prior art solid state watches capable of displaying both the time and calendar data have at least three buttons for selecting the time and the date, and presetting the time and the date registers. Such prior art watches often require two buttons to be simultaneously depressed to provide the time setting sequence. Such multiple button watches obviously induce a complicating factor in reading and setting watches since the user must remember which button provides which function. Moreover, the multiple buttons add an additional expense to the manufacturing cost of the watch and tend to decrease the reliability of the watch. Thus, the switches commonly employed are either magnetic reed switches, which are relatively expensive and require the user to have a permanent magnet to set the watch, or push pins on the side of the watch case which engage a contact within the watch case. These latter switches have the problem of waterproofing openings in the watch case.